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Biomedical subjects

Michio Koide

Publications and source records attributed to Michio Koide.

16 recordsLinked to original sources
PubMed2006

Influence of temperature on growth of Legionella pneumophila biofilm determined by precise temperature gradient incubator.

Bacterial growth is influenced by several different culture conditions. Temperature is one of an essential component which regulates bacterial growth and their morphology. The influence of temperature on the length of bacteria was investigated in broth and on agar in a temperature range from 30.0 degrees C to 47.0 degrees C in 0.5 degrees C steps using a newly developed temperature gradient incubator. The incubator is able to reach a set temperature within 2 h and maintain temperature as accurate as +/-0.1 degrees C of the set temperature. Three Legionella pneumophila serotype 1 strains were incubated for 48 h in BCYE-alpha agar at various temperatures ranging from 30.0 degrees C to 48.0 degrees C and length of bacteria grown at each temperature was microscopically measured. Ability of bacteria to multiply at a given temperature was also determined. L. pneumophila serotype 1 strains ATCC 33152, a clinical isolate Okinawa 02-001 were going to elongate to longer than 100 mum when cultured higher than at 39.5 degrees C and at 41.5 degrees C, respectively. Each strain was unable to multiply when cultured higher than at 44.2 degrees C (ATCC 33152) or at 44.0 degrees C (Okinawa 02-001). Those data would provide insights for establishing regulations in terms of maintaining hot water temperature in a facility where a circulating hot water supply-system is available and contamination with Legionella spp. is likely to happen.

Adaptation, Physiological↗
PubMed2005

In vitro activity of pazufloxacin, tosufloxacin and other quinolones against Legionella species.

OBJECTIVES: The activities of pazufloxacin and tosufloxacin against Legionella spp. were evaluated in vitro and compared with those of other quinolones, macrolides and azithromycin. METHODS: The conventional MICs were determined by the microbroth dilution method. Intracellular activities of drugs were evaluated by a cfu count. The minimal extracellular concentration inhibiting intracellular growth of bacteria (MIEC) was determined by a colorimetric cytopathic assay. RESULTS: MICs of pazuloxacin and tosufloxacin at which 90% (MIC90) of isolates are inhibited in 76 different Legionella spp. strains (38 ATCC strains and 38 clinical isolates) were 0.032 and 0.016 mg/L, whereas the MIC90s of levofloxacin, ciprofloxacin, garenoxacin, erythromycin, clarithromycin and azithromycin were 0.032, 0.032, 0.032, 2.0, 0.125 and 2.0 mg/L, respectively. Pazufloxacin and tosufloxacin at 4x MIC inhibited intracellular growth of Legionella pneumophila SG1 (80-045 strain), as did other quinolones, clarithromycin and azithromycin, whereas erythromycin at 4x MIC did not. MIECs of pazufloxacin, tosufloxacin, levofloxacin, ciprofloxacin and garenoxacin for the strain were 0.063, 0.004, 0.016, 0.032 and 0.008 mg/L respectively, which were superior to those of macrolides and azithromycin. Pazufloxacin showed potent activity against three additional clinical isolates of L. pneumophila SG1, one clinical isolate each of L. pneumophila SG3 and SG5, as well as Legionella micdadei, Legionella dumoffii and Legionella longbeachae SG1. CONCLUSIONS: Pazufloxacin and tosufloxacin, as well as other quinolones, were more potent than macrolides and an azalide. Present data warrant further study on the efficacy of these drugs in the treatment of Legionella infections.

Animals↗
PubMed2005

[Legionnaires' disease with acute renal failure caused by Legionella pneumophilla serogroup 4].

A 77-year-old man who had fever and chest pain was admitted to a neighboring hospital on a diagnosis of pneumonia. Chest X-ray film finding deteriorated despite treatment with 2 g cefotaxime per day. Because of accompanying acute renal failure, he was transferred to our hospital. Hemodialysis with intravenous administration of erythromycin and meropenem resulted in recovery from acute renal failure, and his general condition improved. Because of liver dysfunction, erythromycin was changed to pazufloxacin. Although he was negative for Legionella urinary antigen determined with a rapid assay kit, Binax NOW, his serum titer for Legionella pneumophila serogroup 4 was elevated. Finally, a diagnosis of Legionnaires' disease caused by Legionella pneumophila serogroup 4 was established.

Acute Kidney Injury↗
PubMed2004

Whipple's disease: the first Japanese case diagnosed by electron microscopy and polymerase chain reaction.

A 52-year-old man presented with diarrhea and 20 kg weight loss in one year. Enteroscopy showed diffuse yellow-white shaggy mucosa in the duodenum and jejunum. Biopsies of the duodenal mucosa revealed massive infiltration within the lamina propria by foamy macrophages strongly positive for periodic acid-Schiff stain. Electron microscopy demonstrated numerous bacilli within macrophages of the lamina propria. Tropheryma whipplei DNA was detected by polymerase chain reaction. The definitive diagnosis of Whipple's disease was made. Antibiotic therapy dramatically improved his clinical picture. This is the first Japanese case with Whipple's disease diagnosed by electron microscopy and polymerase chain reaction.

Biopsy, Needle↗
PubMed2003

In vitro and in vivo activity of olamufloxacin (HSR-903) against Legionella spp.

The activity of the fluoroquinolone olamufloxacin (HSR-903) against Legionella spp. was studied in vitro and in vivo. The olamufloxacin MIC at which 50% of isolates are inhibited (MIC50) for 81 different Legionella spp. strains (59 type strains and 22 clinical isolates) was 0.008 mg/L, which was identical to sparfloxacin, whereas the MIC50s for erythromycin, levofloxacin and ciprofloxacin were 0.25, 0.032 and 0.032 mg/L, respectively. Olamufloxacin and sparfloxacin (at 0.008 mg/L) inhibited intracellular growth and subsequent cytotoxicity of L. pneumophila 80-045 in J774.1 macrophages, whereas levofloxacin and ciprofloxacin did not, at the same concentration. When olamufloxacin was given to the infected guinea pigs orally (5 mg/kg of body weight), peak levels in the lung were 3.02 mg/kg at 2 h post-administration, with a half-life of 3.41 h and an AUC0-12 of 12.31 mg.h/kg. The 2 day post-infection bacterial burden of the lung in the animals treated with olamufloxacin (5 and 1.25 mg/kg given orally twice a day) was much lower than in those treated with levofloxacin (same dose as olamufloxacin) or erythromycin (10 mg/kg given orally twice a day). When treated with olamufloxacin (5 mg/kg given orally twice a day) for 7 days, 11 of 12 L. pneumophila-infected guinea pigs survived for 14 days post-infection, as did all 12 guinea pigs treated with levofloxacin (5 mg/kg given orally twice a day) for 7 days. In contrast, only two of 12 animals treated with erythromycin survived and 10 of 11 died in the physiological saline group. Olamufloxacin was as effective as levofloxacin in a guinea pig model of Legionnaires' disease. These data warrant further study of whether olamufloxacin is an option for the treatment of Legionella infections.

Animals↗
PubMed2003

Isolation of Legionella anisa from multiple sites of a hospital water system: the eradication of Legionellacontamination.

For the prevention of nosocomial cases of legionellosis in the Ryukyu University Hospital neonatal wards, we examined nine shower units and a sink tap water unit for the presence of Legionella, over a 6-year period. We isolated Legionella-like organisms (LLO) from showerheads by culturing sediments from the water samples on buffered charcoal yeast extracts (BCYE). We used DNA-DNA hybridization to determine that the organisms were L. anisa. A fingerprinting technique called random amplified polymorphism DNA (RAPD) also showed that all the organisms were identical at the genome level. Replacement of the shower heads harboring colonies of L. anisa prevented further contamination. Nosocomial cases of legionellosis have not been reported from the wards during the period of this survey. This is the first description of the isolation of L. anisa from multiple sites within a hospital, and RAPD analysis suggests that these may be the spread of a single clone.

Cross Infection↗
PubMed2003

A case of nosocomial Legionella pneumophila pneumonia.

We report a case of Legionella pneumophila pneumonia in a patient with interstitial lung disease. Intensive environmental investigations revealed that a system of all-day-running bathwater was the source of infection. In this case, the concentration of L. pneumophila in the hospital bathwater was low. We therefore emphasize that even a low concentration of L. pneumophila in environmental water can cause serious infections to immunocompromised patients in a hospital.

Aged↗
PubMed2002

Induction of apoptosis of human macrophages in vitro by Legionella longbeachae through activation of the caspase pathway.

The cytotoxicity of the facultative intracellular bacterium, Legionella longbeachae, an important cause of legionellosis, was characterised. Apoptosis was induced in HL-60 cells, a human macrophage-like cell line, during the early stages of infection and induction of apoptosis correlated with cytotoxicity. Apoptosis was confirmed by agarose gel electrophoresis of fragmented DNA, surface exposure of phosphatidylserine and propidium iodide labelling of host cell nuclei. The involvement of macrophage infectivity potentiator (Mip) protein, a known virulence factor of L. longbeachae, was also examined. A mip mutant of L. longbeachae induced apoptosis of HL-60 cells but failed to multiply intracellularly, suggesting that intracellular replication of L. longbeachae is not essential for the induction of apoptosis of HL-60 cells. Furthermore, induction of apoptosis of L. longbeachae-infected macrophages was mediated by activation of the caspase pathway but might be independent of tumour necrosis factor-alpha- and Fas-mediated signal transduction pathways.

Apoptosis↗
PubMed2002

Legionella pneumophila pneumonia successfully treated with intravenous ciprofloxacin.

A 69-year-old man developed a cough and fever during treatment with corticosteroid (p.o. and external use) for erythroderma. Chest X-ray films revealed a consolidation shadow in the right upper lung field. Initial treatment with sulbactam sodium/ampicillin followed by imipenem/cilastatin was not effective. A urinary antigen test for Legionella was positive, making for a diagnosis of Legionella pneumonia. Intravenous treatment with ciprofloxacin (CPFX) was remarkably effective. His symptoms, chest X-ray and laboratory data rapidly improved after its initiation. Our findings strongly suggest that intravenous treatment with fluoroquinolones including CPFX should also be a first choice for Legionella pneumonia in Japan.

Aged↗
PubMed2002

Rapidly expanding lung abscess caused by Legionella pneumophila in immunocompromised patients: a report of two cases.

We describe two cases of lung abscess caused by Legionella pneumophila in immunocompromised patients. The first case had been treated initially with 60 mg prednisolone for ulcerative colitis, and L. pneumophila serogroup 1 was isolated from sputum samples after cavitation of the lung lesion. The second case was diagnosed as plasma cell lymphoma at post-mortem examination. L. pneumophila serogroup 5 was isolated from the contents of lung abscess, together with Enterococcus faecium and Prevotella intermedia in the post-mortem examination. Lung abscess caused by Legionella is unusual. Here, we discuss the difficulty of diagnosis of legionellosis in patients with unusual chest radiographic findings.

Adult↗
PubMed2002

[An infection with Legionella pneumophila treated with intravenous ciprofloxacin].

A 60-year-old diabetic man who had had a coronary artery bypass graft operation was admitted to Okaya Enrei Hospital because of coughing, high fever and dyspnea. Chest high-resolution computed tomography scans revealed bilateral pleural effusions and left-sided alveolar shadows and ground glass opacity. These infiltrations in the left lung field showed rapid growth. Legionella pneumonia was diagnosed because of a high titer for Legionella pneumophila antigen in the urine. He was treated with 600 mg per day of parenteral ciprofloxacin for two weeks and 10 mg per day of oral prednisolone for the second week, resulting in improvement of the clinical findings.

Anti-Infective Agents↗